Pump



E. BENEDEK Feb. 5, 1935.

PUMP' 5 Sheets-Sheet l Filed May 23. 1932 Feb. 5, 1935. E, BENEDEK PUMP` Filed May 2:5, 1932 3 Islw-.ets-sheet 2 :ln/vanter,

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Feb. 5, 1935.

E. BENEDEK PUMP , Filed May 23,l 1932 5 Sheets-Sheel 3` Lll gin/vento@EEK EEA/505K.

l Patented Feb. 5, 1935 UNITED STATES PUMP EleklBenedek, Mount Gilead,Ohio, asslgnor to The Hydraulic Press Manufacturing Company, Y MountGilead, Ohio, a corporation of Ohio Application May 23, 1932, Serial No.613,011

11 Claims. (Cl. 10S-37) dividual hydrostatically balanced valve for eachI cylinder- An object of the present invention is to simplify andotherwise improve the construction and operation of pumps of the typeabove referred to.

The present application discloses a similar type of variable deliverypump having a single rotary valve for controlling the discharge from thesev- 20 eral cylinders.

Other more specific objects and advantages will appear from thefollowing description of an illustrative embodiment of the presentinvention.

In the accompanying drawings:

Figure 1 is a vertical longitudinal sectional view of a pump constructedin accordance with the present invention.

` Fig. 2 is a vertical transverse sectional view on the line 2 2 of Fig.1.

30 Fig. 3 is a horizontal sectional view on the line 3 3 of Fig. 2. Fig.4 is a fragmentary detail of the rotary valve shown particularly inFig.`1.

Figs. 5, 6, and 7 are sectional views of the valve taken substantiallyalong the lines 5 5, 6 6, and 7 7, respectively, of Fig. 4.

The. pump shown is enclosed within an appropriate housing 10 whose base11 forms a liquid reservoir. A block 12, rigidly mounted on appropriatebrackets 13 within the base 11, supports a plurality of uprightcylinders 14 which in turn support a head structure 15.

A crank shaft 16 in the upper part of the housing 10 is provided with aplurality of circular cheek plates 17 journalled in individualantifriction bearings 18 secured within the'A head structure 15. Crankpins 19 supported by and between successive cheek plates 17 areconnectedthrough appropriate crank arms 20 with pistons 50 21 reciprocable Withinthe cylinders 14. In this instance each crank arm 20 is equipped with aball 22 closely tted for rocking action within a cylindrical pocket 23formed in the associated piston 21, each ball being retained by a sleeve24 screwed into the pocket. The successive crank pins 19 are equallyspaced about the axis of the crank shaft.

A port 25 inthe base of each cylinder 14 communicates with alongitudinal bore 26 formed in the block 12. A Valve element 27, closelyfitted for rotation within the bore 26, cooperates with the severalports 25 to control communication of eachv cylinder with a-supplypassage 28 and a discharge passage 29. The supply passage 28 isconnected to a pipe 30 constituting the return side of a hydrauliccircuit and the discharge passage 29 is connected to a pipe 31constituting the high pressure or working side of the circuit. The valveelement 27 is rotated synchronously with and by the crank shaft 16through appropriate means such as mitre gears 32, shaft 33 and mitregears 34.

In this instance the valve element 27 is provided with end heads 35 and36 and with a plurality of integral collars 37. An annular space 38between the end head 35 and adjacent collar 37 communicates at all timeswith a passage 39 which leads to the discharge passage 29. (See Fig.l3.) The spaces 40 between successive collars 37 communicate with thesupply passage 28 through individual passages 41.

To oppositely spiraled ribs 42 extend laterally from diametricallyoppositepoints on each collar 37 and merge at their extremities tocompletely enclose a substantially triangular depression or pocket 43.The successive pockets 43 are equally spaced about the axis of the valveelement, and each has a port 44 'in the bottom thereof whichcommunicates with a longitudinal passage 45 leading to the annular space38.

The arrangement is such that during rotation of the valve element 27, inthe position of Fig. 1, each cylinder port 25 communicates alternatelywith an adjacent pocket 43 and space 40. The rotation of the valve is sotimed with respect to the crank shaft that, during each upward orsuction stroke of each piston, port 25 communicates with the supplypassage 28 through port 41 and space 40, and during each pressurevstroke the port 25 communicates with the dis-l charge passage 29 throughpassageA 39, space 38,

passage 45 and pocket 43. That condition exists 'so vlong as the valve27 is in the position shown with the port 25 adjacent the collar 37whereit coacts with the wide portion of the pocket 43.

If the valve element 27 be moved lengthwise s of its cooperating pocket'43, each cylinder then communicates with the space 38 and'discharge 5have in this instance provided hydraulic means for this purposeincluding a hydraulic connection 46 which leads to the right end 47 ofthe valve bore, and through which hydraulic pressure may be applied tothe end head 36 to shift the valve element lengthwise against theresistance of a'spring 48.

Provision is made for preventing the creation I of excessive pressureswithin each cylinder that might otherwise result during each pressurestroke from a momentary trapping of the liquid therein as each rib 42passes beneath each cylinder port 25 during rotation of the valveelement. In this instance this is accomplished by the provision of apassage 49 which leads from each cylinder port 25 to a passage 50communicating with the discharge passage 29. (See Figs. 1 and 2.) Eachpassage 49 is controlled by an outwardly opening check valve 51 which isheld lightly against its seat by a, spring 51'. It will thus be notedthat whenever the pressure in any cylinder 25 tends to exceed thepressure in the delivery passage 29 the associated check valve 50 willimmediately open to thereby permit the cylinder to discharge momentarilyinto the delivery passage 29.

A high pressure relief valve 52 connected to the delivery passage 29limits the pressure therethe longitudinal position of the valve element27 all of the chambers 40 therein are open to the supply passage28,through the passages 41, so that each cylinder 14 is always open tothe supply passage 28 through each suction stroke. Under some conditionsof operation, however, the liquid supplied to the supply passage 28 fromthe return side 30 of the circuit may be insufficient to satisfy thedemands of the pump, causing cavitation in the liquid column and otherobjectionable condtions. Provision is therefore made for supplyingliquid from the reservoir in the base 11 of the pump casing to therebyautomatically compensate for such insufliciencies as and when theyoccur.

For this purpose the pump shown is provided" with a plurality ofinwardly opening check valves 53 immersed within the liquid reservoir`11 and each in constant communication with one of the chambers 40 inthe valve element 27 through a passage 53', regardless of the rotativeor longitudinal position of the valve.

A pressure relief valve 54, connected to the supply passage 28 through apassage 55, limits the pressure within the return side 30 of the circuitand permits the escape of liquid from the passage 28 inex'cess of thatdemanded by the pump. A

In the pump shown each of the several pockets 43 in the valve element 27is formed by ribs 42 which make equal angles with the connected collar37, although the ribs 42 may be disposed at diiferent angles, one ofthem for instance extending substantially parallel to the axis of thevalve and the other disposed at an acute angle thereto. Various otherchanges may be made in the embodiment of the inventionl hereinabovespecifically described without departingfrom or lsacriii'cing theadvantages of the invention as dcfined in the appended claims.

1. In a variable delivery hydraulic pump the4 Throughout the operationand irrespective of acting pistons, a liquid supply passage, a liquiddischarge passage, rotary valve means having longitudinally-taperedchambers for connecting each cylinder alternately with said supply anddischarge passages, and means for shifting said valve meanslongitudinally to vary the quantity of liquid delivery.

2. In a variable delivery hydraulic pump the combination of a pluralityof cylinders and coacting pistons, a liquid supply passage, a liquiddischarge passage, and a rotary valve having means for connecting eachcylinder with said supply and discharge passages alternately duringrotation thereof, said valve being longitudinally adjustable, and saidlast named means being arranged to vary the quantity of liquid deliverybetween each cylinder and said discharge passage in response tolongitudinal movement of said valve.

3. In a Variable delivery hydraulic pump the combination of a pluralityof cylinders and coacting pistons, a liquid supply passage, a liquiddischarge passage, a rotary valve, said valve having means formaintaining communication between each cylinder and said supply passagethroughout each suction stroke, said valve also having means foreffecting communication between each cylinder and said discharge passageduring each pressure stroke, said last named means comprising aplurality of longitudinally tapered chambers in said valve forcommunication with the respective cylinders, said valve and chambersbeing shiftable longitudinally to thereby vary the quantity of liquiddelivery between each cylinder and said discharge passage.

4. In a variable delivery hydraulic pump the combination of a pluralityof cylinders and coacting pistons, a liquid supply passage, a liquiddischarge passage, a valve bore having com -between each cylinder andsaid discharge passage.

5. In a variable delivery hydraulic pump the combinationof a pluralityof cylinders and coacting pistons, a liquid supply passage, a liquiddischarge passage, a valve bore, a longitudinallyadjustable valverotatable in said bore and coacting therewith to form. an annularchamber, said discharge passage communicating with said chamber, saidvalve having a pluralityof longitudinally tapered chambers each arrangedto intermittently communicate with one of said cylinders during rotationof said valve, a passage in said valve connecting each of said lastnamed chambers with said annular chamber, said valve also having meansfor effecting intermittent communication between each cylinder and saidsupply passage, and means for shifting said valve longitudinally to varythe quantity of liquid delivery between 'said cylinders and saiddischarge passage.

6. In a variable delivery hydraulic pump the combination of a housinghaving a liquid reservoir, a plurality of cylinders and coacting pistonsin said housing, a supply passage, a discharge passage, a valve bore, alongitudinally adjustable valve having longitudinally-tapered chambersand rotatable in said bore to eil'ect communication between eachcylinder and said supply and discharge passages alternately, means foradjusting said valve longitudinally to vary the quantity of liquiddelivery between said cylinders and passages, and means for admittingliquidA from said reservoir to said rotatable valve bore and cylin dersto automatically compensate for any under supply of liquid that mayoccur in said supply passage.

7. In a variable delivery hydraulic pump, the combination of a housinghavi"g a liquid reservoir', a plurality of cylinders and co-actingpistons in said housing, a supply passage, a discharge passage, a valvebore, a longitudinally-I adjustable valve having longitudinally-taperedchambers. and rotatable in said bore to effect communication betweeneach cylinder and said supply and discharge passages alternately, meansfor adjusting said valve longitudinally to vary the quantity of liquiddelivery between said cylinders and passages and means comprising aunidirectional valve communicating with said reservoir whereby said pumpdraws liquid into said bore and cylinders from said reservoir toautomatically compensate for any under-supply of acting pistons, a,liquid supply passage, a liquid discharge passage, rotary valve meanshaving longitudinally-tapered chambers for connecting each cylinderalternately with said supply and discharge passages, and pressureresponsive means for shifting said valve means longitudinally to varythe quantity of liquid delivery, said pressure responsive meanscomprising a piston head associated with said valve means to urge saidvalve means in one direction and yielding means for urging said valvemeans in the opposite direction.

10. In a variable delivery hydraulic pump, the combination of aplurality of cylinders and coacting pistons, a liquid supply passage, aliquid discharge passage, rotary valve means havinglongitudinally-tapered chambers associated in pairs for connecting eachcylinder alternately with said .supply and discharge passages, and meansfor shifting said valve means longitudinally to vary the quantity ofliquid delivery, said valve means being disposed in a longitudinalhorizontal direction in said pump. I

11. In a variable delivery hydraulic pump, thecombination of a pluralityof cylinders and coacting pistons, a liquid supply passage, a liquiddischarge passage, rotary valve means having longitudinally-taperedchambers associated in pairs for connecting each cylinder alternatelywith said supply and discharge passages, the chambersof each pair beingseparated by a diagonally-disposed ridge on said valve means and meansfor shifting said valve means longitudinally to vary the quantity ofliquid delivery, said valve means being disposed in a longitudinalhorizontal direction in said pump and passing continuously therethrough.

- ELEK BENEDEK.

